Process for the preparation of bitumen-polymer compositions, application of the compositions obtained to the production of coatings and polymer master solution for obtaining the same compositions

A process for the preparation of a bitumen-polymer composition which comprises

• (a) producing at a temperature of between 100.degree. C. and 230.degree. C. a mixture of
• (i) a bitumen;
• (ii) a linear block copolymer of styrene and a conjugated diene selected from the group consisting of butadiene, isoprene, chloroprene, carboxylated butadiene and carboxylated isoprene, said block copolymer being used in a quantity of from 0.5% to 25% by weight of bitumen and having a weight-average molecular weight of between 150,000 and 350,000 and a structure of A-B with A denoting a polymer block consisting of a polystyrene block and B denoting a polymer block consisting of conjugated diene units, the block copolymer having a styrene content which comprises between 5.2% and 14.7% by weight of the copolymer;
• and
• (iii) a coupling agent containing at least one sulphur-donor compound and used in an amount to provide a quantity of sulphur representing, by weight, 0.1% to 10% of the weight of the linear block copolymer of styrene and conjugated diene;
• and
• (b) keeping the mixture thus produced at a temperature of between 100.degree. C. and 230.degree. C. and with stirring for a period of at least ten minutes.

A process for the preparation of a bitumen-polymer composition which comprises

• (a) producing at a temperature of between 100.degree. C. and 230.degree. C. a mixture of
• (i) a bitumen;
• (ii) a linear block copolymer of styrene and a conjugated diene selected from the group consisting of butadiene, isoprene, chloroprene, carboxylated butadiene and carboxylated isoprene, said block copolymer being used in a quantity of from 0.5% to 25% by weight of bitumen and having a weight-average molecular weight of between 150,000 and 350,000 and a structure of A-B with A denoting a polymer block consisting of a polystyrene block extended on the B side by a random copolymer of styrene and of the conjugated diene and B denoting a polymer block consisting of conjugated diene units, the block copolymer having an overall weight content of styrene not exceeding 20% and a styrene content in the form of a polystyrene block in the polymer block A comprised between 5.2% and 14.7% by weight of the copolymer;
• and
• (iii) a coupling agent containing at least one sulphur-donor compound and used in an amount to provide a quantity of sulphur representing, by weight, 0.1% to 10% of the weight of the linear block copolymer of styrene and conjugated diene;
• and
• (b) maintaining the mixture thus produced at a temperature of between 100.degree. C. and 230.degree. C. with stirring for a period of at least ten minutes.

A process for the preparation of a bitumen-polymer composition which comprises:

• (a) producing at a temperature of between 100.degree. C. and 230.degree. C. a mixture of
• (i) a bitumen:
• (ii) a linear block copolymer of styrene and a conjugated diene selected from the group consisting of butadiene, isoprene, chloroprene, carboxylated butadiene and carboxylated isoprene, said block copolymer being used in a quantity of from 0.5% to 25% by weight of bitumen and having a weight-average molecular weight of between 170,000 and 250,000 and a structure of A-B with A denoting a polymer block consisting of a polystyrene block extended on the B side by a random copolymer of styrene and of the conjugated diene and B denoting a polymer block consisting of conjugated diene units, the block copolymer having an overall weight content of styrene not exceeding 20% and a styrene content in the form of a polystyrene block in the polymer block A comprised between 5.2% and 14.7% by weight of the copolymer;
• and
• (iii) a coupling agent containing at least one sulphur-donor compound and used in an amount to provide a quantity of sulphur representing, by weight, 0.1% to 10% of the weight of the linear block copolymer of styrene and conjugated diene;
• and
• (b) maintaining the mixture thus produced at a temperature of between 100.degree. C. and 230.degree. C. with stirring for a period of at least ten minutes.